BACKGROUND: The red flour beetle Tribolium castaneum is an emerging insect model organism representing the largest insect order, Coleoptera, which encompasses several serious agricultural and forest pests. Despite the ecological and economic importance of beetles, most insect olfaction studies have so far focused on dipteran, lepidopteran, or hymenopteran systems. RESULTS: Here, we present the first detailed morphological description of a coleopteran olfactory pathway in combination with genome-wide expression analysis of the relevant gene families involved in chemoreception...

Entomopathogenic bacteria produce insecticidal proteins that accumulate in inclusion bodies or parasporal crystals (such as the Cry and Cyt proteins) as well as insecticidal proteins that are secreted into the culture medium. Among the latter are the Vip proteins, which are divided into four families according to their amino acid identity. The Vip1 and Vip2 proteins act as binary toxins and are toxic to some members of the Coleoptera and Hemiptera. The Vip1 component is thought to bind to receptors in the membrane of the insect midgut, and the Vip2 component enters the cell, where it displays its ADP-ribosyltransferase activity against actin, preventing microfilament formation...

The insulin and insulin-like signaling (IIS) pathway exists in a wide range of organisms from mammals to invertebrates and regulates several vital physiological functions. A phylogenetic analysis have indicated that insulin receptors have been duplicated at least twice among vertebrates, whereas only one duplication occurred in insects before the differentiation of Coleoptera, Hymenoptera, and Hemiptera. Thus, we cloned two putative insulin receptor genes, T.cas-ir1 and T.cas-ir2, from T. castaneum and determined that T...

Monochamus alternatus Hope is the main vector in China of the Pine Wilt Disease caused by the pine wood nematode Bursaphelenchus xylophilus. Although chemical control is traditionally used to prevent pine wilt disease, new strategies based in biological control are promising ways for the management of the disease. However, there is no deep sequence analysis of Monochamus alternatus Hope that describes the transcriptome and no information is available about gene function of this insect vector. We used next generation sequencing technology to sequence the whole fourth instar larva transcriptome of Monochamus alternatus Hope and successfully built a Monochamus alternatus Hope transcriptome database...

The leaf beetle Ambrostoma quadriimpressum (Coleoptera: Chrysomelidae) is a predominant forest pest that causes substantial damage to the lumber industry and city management. However, no effective and environmentally friendly chemical method has been discovered to control this pest. Until recently, the molecular basis of the olfactory system in A. quadriimpressum was completely unknown. In this study, antennae and leg transcriptomes were analyzed and compared using deep sequencing data to identify the olfactory genes in A...

Longhorn wood-boring beetles (Coleoptera: Cerambycidae) use olfactory cues to find mates and hosts for oviposition. Tetropium fuscum (Fabr.) is an invasive longhorned wood-boring beetle originating from Europe that has been established in Nova Scotia, Canada, since at least 1990. This study used single sensillum recordings (SSR) to determine the response of olfactory receptor neurons (ORNs) in the antennal sensilla of male and female T. fuscum to different kinds of olfactory cues, namely host volatiles, non-host volatiles, the aggregation pheromone of T...

The response of antennal olfactory receptor neurons (ORNs) of Monochamus galloprovincialis to several odourants was tested using single sensillum electrophysiology. Behaviourally active pheromone, and kairomone (host and sympatric bark beetle pheromone) odours were tested alongside smoke compounds released by burnt wood that are potentially attractive to the insect. The antennae bore several types of sensilla. Two plate areas in the proximal and distal ends of each antennal segment were covered with basiconic sensilla that responded to the odour stimuli...

Working on the hypothesis that an important function of the lamellate antennae of adult male beetles belonging to the genus Rhipicera is to detect scent associated with female conspecifics, and using field observations, anatomical models derived from X-ray microcomputed tomography, and scanning electron microscopy, we have investigated the behavioral, morphological, and morphometric factors that may influence molecule capture by these antennae. We found that male beetles fly upwind in a zigzag manner, or face upwind when perching, behavior consistent with an animal that is tracking scent...

A novel cell line, NRCAN-Tb521, was developed from larvae of the longhorn beetle Tylonotus bimaculatus (Coleoptera: Cerambycidae), a pest of North American ash trees. The cell line has been successfully passaged more than 50 times and displayed very strong attachment to the substrate and a modal chromosomal count distribution of 19. Sequencing of a 649 bp fragment of the mitochondrial cytochrome oxidase I gene confirmed the identity of NRCAN-Tb521 as T. bimaculatus. The response of the cell line to 20-hydroxyecdysone and diacylhydrazine ecdysone agonist insecticides was also studied...

BACKGROUND: The red turpentine beetle (RTB), Dendroctonus valens LeConte (Coleoptera: Curculionidae, Scolytinae), is a destructive invasive pest of conifers which has become the second most important forest pest nationwide in China. Dendroctonus valens is known to use host odors and aggregation pheromones, as well as non-host volatiles, in host location and mass-attack modulation, and thus antennal olfaction is of the utmost importance for the beetles' survival and fitness. However, information on the genes underlying olfaction has been lacking in D...

Knowledge on neuropeptide receptor systems is integral to understanding animal physiology. Yet, obtaining general insight into neuropeptide signalling in a clade as biodiverse as the insects is problematic. Here we apply fluorescent analogues of three key insect neuropeptides to map renal tissue architecture across systematically chosen representatives of the major insect Orders, to provide an unprecedented overview of insect renal function and control. In endopterygote insects, such as Drosophila, two distinct transporting cell types receive separate neuropeptide signals, whereas in the ancestral exopterygotes, a single, general cell type mediates all signals...

BACKGROUND: The metallic green beetle, Anomala corpulenta (Coleoptera: Scarabaeidae: Rutelinae), is a destructive pest in agriculture and horticulture throughout Asia, including China. Olfaction plays a crucial role in the survival and reproduction of A. corpulenta. As a non-model species, A. corpulenta is poorly understood, and information regarding the molecular mechanisms underlying olfaction in A. corpulenta and other scarab species is scant. METHODOLOGY/PRINCIPLE FINDINGS: We assembled separate antennal transcriptome for male and female A...

The emerald ash borer, Agrilus planipennis (Coleoptera: Buprestidae) (EAB), is an invasive species causing unprecedented levels of mortality to ash trees in its introduced range. The female-produced sex pheromone of EAB has been shown to contain the macrocyclic lactone (3Z)-dodecen-12-olide. This compound and its geometrical isomer, (3E)-dodecen-12-olide, have been demonstrated previously to be EAG active and, in combination with a host-derived green leaf volatile, (3Z)-hexenol, to be attractive to male EAB in green prism traps deployed in the ash tree canopy...

We present the first antennal transcriptome sequencing information for the yellow mealworm beetle, Tenebrio molitor (Coleoptera: Tenebrionidae). Analysis of the transcriptome dataset obtained 52,216,616 clean reads, from which 35,363 unigenes were assembled. Of these, 18,820 unigenes showed significant similarity (E-value <10(-5)) to known proteins in the NCBI non-redundant protein database. Gene ontology (GO) and Cluster of Orthologous Groups (COG) analyses were used for functional classification of these unigenes...

BACKGROUND: Chemoreception is based on the senses of smell and taste that are crucial for animals to find new food sources, shelter, and mates. The initial step in olfaction involves the translocation of odorants from the periphery through the aqueous lymph of the olfactory sensilla to the odorant receptors most likely by chemosensory proteins (CSPs) or odorant binding proteins (OBPs). RESULTS: To better understand the roles of CSPs and OBPs in a coleopteran pest species, the red flour beetle Tribolium castaneum (Coleoptera, Tenebrionidae), we performed transcriptome analyses of male and female antennae, heads, mouthparts, legs, and bodies, which revealed that all 20 CSPs and 49 of the 50 previously annotated OBPs are transcribed...

The genomes of the migratory locust Locusta migratoria and the termite Zootermopsis nevadensis were mined for the presence of genes encoding neuropeptides, neurohormones, and their G-protein coupled receptors (GPCRs). Both species have retained a larger number of neuropeptide and neuropeptide GPCRs than the better known holometabolous insect species, while other genes that in holometabolous species appear to have a single transcript produce two different precursors in the locust, the termite or both. Thus, the recently discovered CNMa neuropeptide gene has two transcripts predicted to produce two structurally different CNMa peptides in the termite, while the locust produces two different myosuppressin peptides in the same fashion...

The lesser mealworm, Alphitobius diaperinus, is a serious cosmopolitan pest of commercial poultry facilities because of its involvement in structural damage to poultry houses, reduction in feed conversion efficiency, and transfer of avian and human pathogens. Cry3Aa, Cry3Bb, and Cry8Ca insecticidal proteins of Bacillus thuringiensis are used to control coleopteran larvae. Cadherins localized in the midgut epithelium function as receptors for Cry toxins in lepidopteran, coleopteran, and dipteran insects. Previously, we demonstrated that the truncated cadherin (DvCad1) from Diabrotica virgifera virgifera, which consists of the C-terminal cadherin repeats (CR) 8-10 and expressed in Escherichia coli, enhanced Cry3Aa and Cry3Bb toxicity against several coleopteran species...

Chemosensory proteins (CSPs) play important roles in chemical communication by insects, as they recognize and transport environmental chemical signals to receptors within sensilla. In this study, we identified HoblCSP1 and HoblCSP2 from a cDNA library of Holotrichia oblita antennae, successfully expressed them in E. coli and purified them by Ni ion affinity chromatography. We then measured the ligand-binding specificities of HoblCSP1 and HoblCSP2 to 50 selected ligands in a competitive binding assay. These results demonstrated that HoblCSP1 and HoblCSP2 have similar ligand-binding spectra...